I regularly put DE in their dust bathing spots, but every time I do, they move to a different spot. They do not like the DE. I have close to 80 birds and their run is huge. I put some DE in all the nest boxes too. But now they have lice. How can I get them to dust bathed in the DE? Do I need to put the DE throughout the entire run? I'll need at least 4 or 5 bags for that. It's getting ready to rain the next few days, so it will have to wait.